Ferrous alloys



United States Patent (Mike 3,330,651 FERROUS ALLOYS Charles N. Younkin, Unity Township, Westmorelaud County, Pa., assignor to Latrobe Steel Company, a corporation of Pennsylvania No Drawing. Filed Feb. 1, 1965, Ser. No. 429,660 4 Claims. (Cl. 75123) This invention relates to ferrous alloys and particularly to an improved high manganese wear resistant steel. High manganese steels such as the well-known Hadfield manganese type steel have long been known and used for conditions of severe pounding impact and abrasion such as occurs in shot blast and crusher liners, hammers, wearing blades, dredge bucket, switch points, excavating bucket teeth, and the like. It has long been the desire of the industry to provide a steel alloy having improved resistance to the severe pounding impact and abrasion characteristic of the aforementioned uses without the addition of expensive alloying ingredients.

I have discovered an alloy having the resistance to severe pounding impact equivalent to Hadfield manganese type steel together with markedly improved resistance to abrasion. The alloy of my invention otherwise has the standard metallurgical characteristics of Hadficld manganese type steels.

The broad composition of my alloy is:

C-about 1% to about 3% Mnabout 10% to about 14% Si2% max.

Ni-0% to about 4% Ti-about 0.5% to about 5% The balance iron with residual impurities in ordinary amounts, the titanium being combined with carbon in the weight ratio of about 4:1 to form titanium carbide.

While the alloy of this invention may fall within the range of a concentration of alloying elements just enumerated, it is generally desirable to hold the composition within the following somewhat narrower range for maXi mum effectiveness.

C-about 1.15 to about 2.25% Mn-about 12% to about 13% Siabout 0.15% to about 0.75% Niabout 0% to about 4% Ti-about 0.5 to about 3.5%

TABLE I.-CHEMISTRY Alloy Designation C I Si I Mn S P Ti 3,330,651 Patented July 11, 1967 Surface hardness and Charpy impact tests were made and the values are set out in the following Table H.

TABLE II.SURFAOE HARDNESS Alloy Aust., 1,850 F., Hour After Shot Charpy Impact Water Quench Peening As-Quenched WR239 187 BHN Rc 240+, 184 WR240 212 BHN. 116, 11 117 WR241 217 BHN 95, 91, 88 WR-242 217 BEN 82 WR-282I 27 NIIIIIIIIIIIIII Photomicrographs were made following a standard Nital etch and the structure appears as follows:

TABLE III.STRUCTURE Samples of each of the alloys were subject to abrasion tests and the results appear in Table IV.

TABLE IV Percent improvement in Alloy designation: abrasion resistance WR-240 3.6 WR-241 28.6 WR-242 3 1.1

I have found that while the presence of titanium combined with carbon markedly aifects the abrasion resistance it does not appear to otherwise affect the other basic metallurgical characteristics of the steel. There is no alteration in hardening characteristics so long as sufiicient excess carbon is added to combine with the titanium and leave sufficient carbon for hardening ability. This means that the amount of carbon present in any given allow should be the amount desired to give a selected hardening ability plus an amount equal to combine with the titanium as titanium carbide in the weight ratio of titanium to carbon of 4:1.

While I have described certain present preferred embodiments of my invention, it will be understood that this invention may be otherwise embodied within the scope of the following claims.

I claim:

1. An abrasion resisting, high impact resisting alloy consisting essentially of about 1% to about 3% carbon, about 10% to about 14% manganese, about 2% maximum silicon, 0 to about 4% nickel, about 0.5 to 5% titanium and the balance iron with residual impurities in ordinary amounts, said titanium being combined with carbon as titanium carbide.

2. An abrasion resisting, high impact resisting alloy consisting essentially of about 1.15% to about 2.25 carbon, about 12% to about 13% manganese, about 0.15% to about 0.75 silicon, 0 to about 4% nickel, about 0.5% to 5% titanium and the balance iron with residual impurities in ordinary amounts, said titanium being combined with carbon as titanium carbide.

3. An abrasion resisting, high impact resisting alloy consisting essentially of about 1.5% carbon, about 12% manganese, about 0.25% silicon, about 1.5 titanium and the balance iron with residual impurities in ordinary 4 amounts, said titanium being combined with carbon as References Cited tltamlm UNITED STATES PATENTS 4. An article made from an alloy consisting essentially of about 1% to about 3% carbon, about 10% to about 846,979 3/1907 churchwood 75 123 14% manganese, about 2% maximum silicon, O to about 5 981,575 1/1911 Kohlhaas 75123 4% nickel, about 0.5% to 5% titanium and the balance 1,111,710 9/ 1914 W l 75123 iron with residual impurities in ordinary amounts, said i;

titanium being combined with carbon as titanium carbide and characterized by high resistance to abrasion, high impact resistance and the presence of substantially uniformly 1O HYLAND BIZOT Pr'mary Examiner distributed titanium carbide. P. WEINSTEIN, Assistant Examiner. 

1. AN ABRASION RESISTING, HIGH IMPACT RESISTING ALLOY CONSISTING ESSENTIALLY OF ABOUT 1% TO ABOUT 3% CARBON, ABOUT 10% TO ABOUT 14% MANGANESE, ABOUT 2% MAXIMUM SILICON, 0 TO ABOUT 4% NICKEL, ABOUT 0.5% TO 5% TITANIUM AND THE BALANCE IRON WITH RESIDUAL IMPURITIES IN ORDINARY AMOUNTS, SAID TITANIUM BEING COMBINED WITH CARBON AS TITANIUM CARBIDE. 